I've been searching for an easy-to-use IME for transliterated Sanskrit/Pali, but everything seems either overly complicated or difficult to obtain, e.g. requiring a Mac or something else less universally applicable.

I have for the last few years been using an IME for transliterated Chinese, called Pinyinput (also available in a Mac version), which is extremely easy. You just type the letter followed by the numbers 1, 2, 3, or 4 to have the corresponding tone mark appear over your letter. It's so much easier than fiddling around with other methods.

Example:

Alt+Shift to toggle between IME. (In this case the Chinese appears.)

Śākyamuni = S2a1kyamuni

As you can see, it super fast and easy. However, as this is actually for Chinese it only has a couple of the diacritical marks needed in Sanskrit/Pali; namely the accute ( ´ ) and the macron ( ¯ ).

All that would be needed to modify this system for Sanskrit/Pali would be the tilde ( ˜ ) and the dot ( . ) below/above consonants.

When I spoke with the developer of Pinyinput about it he said;

Pinyinput was written in C++ and the source code has been released under the GPL so is available for anyone else to download and/or modify if they wish, so long as they also release the source code for their changes.

It compiles cleanly using Visual Studio Express 2008 and is fairly modular, so I don't expect it would be too hard for someone who knew what they were doing to adapt it for another writing system.

Unfortunately, I lack the techsaviness for this type of thing. So hopefully either we can find a developer on here who might be willing to do the modifications, or if we can get enough people to pledge a donation toward a Kickstarter project for this to be done...

This has been extremely invaluable for me in the Chinese version for essays, papers, discussions, etc.. Just wish we could have a version of it for Sanskrit/Pali input.